Rose oil is simple inhalation so you could diffuse it while you are doing your meditation if you like - or simply put the bottle under your nose while you naturally inhale (not deep breathe) a few times

I buy the 100% therapeutic grade 0.5oz (it last well over a month) from here

Essential Oils, Soap Making Supplies & More | Bulk Apothecary

But you can buy them anywhere - just be sure they are at least 80% therapeutic gradevto be effective